EP 0702134 A3 19960703 - An exhaust gas purification device for an engine
Title (en)
An exhaust gas purification device for an engine
Title (de)
Abgasreinigungseinrichtung für eine Brennkraftmaschine
Title (fr)
Dispositif de purification de gaz d'échappement pour moteur à combustion
Publication
Application
Priority
JP 22162494 A 19940916
Abstract (en)
[origin: EP0702134A2] The exhaust gas purification device according to the present invention utilizes two NOx absorbents (7a,7b) in order to remove NOx from the exhaust gas of an engine (1) operated at a lean air-fuel ratio. The NOx absorbents (7a,7b) are disposed, in series, in the exhaust passage (3) of the engine and a nozzle (12a) for supplying a reducing agent is disposed in the exhaust passage at a position between the two NOx absorbents. Further, the device includes switching valves (5) for changing the direction of the exhaust gas flow in the exhaust gas passage. When the switching valves are set to direct the exhaust gas flow to one direction, the exhaust gas first flows through one of the NOx absorbent (first NOx absorbent) (7a), and after passing through the first NOx absorbent, the reducing agent is supplied to the exhaust gas before it flows into the other NOx absorbent (second NOx absorbent) (7b). Thus, the first NOx absorbent (7a) absorbs NOx in the exhaust gas, and the NOx absorbed by the second NOx absorbent is released from the second NOx absorbent. When the switching valves (5) are switched, the exhaust gas flows in the opposite direction, and flows through the second NOx absorbent (7b) and the first NOx absorbent (7a) in this order. In this case, the second NOx absorbent (7b) absorbs NOx in the exhaust gas, and the NOx absorbed by the first NOx absorbent (7a) is released and reduced to N2. Therefore, by reversing the direction of the exhaust gas periodically, the absorbing operation of NOx and releasing/reducing operation of NOx are performed by two NOx absorbents alternately. Thus, it becomes possible to remove NOx in the exhaust gas continuously while the NOx absorbents are prevented from being saturated by the absorbed NOx. <IMAGE>
IPC 1-7
IPC 8 full level
B01D 53/94 (2006.01); F01N 3/08 (2006.01); F01N 3/18 (2006.01); F01N 3/24 (2006.01); F01N 3/28 (2006.01); F01N 3/30 (2006.01); F01N 3/20 (2006.01); F01N 3/22 (2006.01); F01N 13/04 (2010.01); F02B 1/04 (2006.01)
CPC (source: EP US)
B01D 53/9481 (2013.01 - EP US); B01D 53/9495 (2013.01 - EP US); F01N 3/0842 (2013.01 - EP US); F01N 3/0871 (2013.01 - EP US); F01N 3/0878 (2013.01 - EP US); F01N 13/011 (2014.06 - EP US); F01N 3/22 (2013.01 - EP US); F01N 2270/00 (2013.01 - EP US); F01N 2410/12 (2013.01 - EP US); F01N 2610/03 (2013.01 - EP US); F01N 2610/04 (2013.01 - EP US); F02B 1/04 (2013.01 - EP US)
Citation (search report)
- [YA] US 4315895 A 19820216 - BRAMER HENRY C, et al
- [Y] DE 3101053 A1 19830324 - BERGWERKSVERBAND GMBH [DE]
- [A] EP 0573672 A1 19931215 - TOYOTA MOTOR CO LTD [JP], et al
- [A] DE 4342062 A1 19940616 - TOYOTA MOTOR CO LTD [JP]
- [A] PATENT ABSTRACTS OF JAPAN vol. 10, no. 373 (C - 391) 12 December 1986 (1986-12-12)
- [DA] PATENT ABSTRACTS OF JAPAN vol. 11, no. 332 (C - 455) 29 October 1987 (1987-10-29)
Designated contracting state (EPC)
DE FR GB
DOCDB simple family (publication)
EP 0702134 A2 19960320; EP 0702134 A3 19960703; EP 0702134 B1 19990609; DE 69510144 D1 19990715; DE 69510144 T2 20000309; JP 3119088 B2 20001218; JP H0886213 A 19960402; US 6409973 B1 20020625
DOCDB simple family (application)
EP 95114465 A 19950914; DE 69510144 T 19950914; JP 22162494 A 19940916; US 52345595 A 19950905